High performance aircraft have flaps along parts of the leading and trailing edges of the wings that pivot but do not extend like the flaps of, for example, commercial airliners. It is well-known to provide seal strips over the gaps between the wing surfaces and the flap surfaces. Where portions of the wings and the flaps have doubly-curved surfaces, such as, for example, at the locations of flap actuators, it is previously known to provide seal strips that are of stainless steel, are tapered in the widthwise direction, and have spaced-apart notches along the thinner edges that form a series of fingers. The seal strips are attached along their thicker edges to the wings so that the fingers extend over the flaps. As the fingers of the sealing strips flex during pivotal movements of the flaps relative to the wings, the tips of the fingers also move closer together or farther apart, depending on the particular geometry, so as to conform to the repositioning of the doubly-curved surfaces of the flaps.
The notches in the sealing strips prevent the sealing strips from fully covering the gaps between the wings and flaps, thus allowing air to intrude into the gap and produce perturbations of the air flow over the seal strip. Such perturbations not only increase drag, but also contribute to increased RF energy, which is undesirable for low observable aircraft. It would be advantageous to eliminate air intrusion into the gap and to prevent disruptions in the smoothness of the flow along a seal strip. There is, accordingly, a need for a sealing strip structure that fully covers the gaps between the wings and flaps of high performance aircraft along portions where the wings and flaps are doubly curved.